for example my comments about the KEF R1 were in a reasonable sized room w a lot of bric a brac diffusion… a very well sorted high quality SWARM and a chain : SOTA > Jelco > Dyna XV-1S > Cary top of line tube phono > Herron line stage and monoblocks… the Digital side 100 % Rockna….
a major dude music lover…. he did trade the for a Gershman..
maybe he will weigh in here…
I don't have any experience with the speakers you mentioned, other than the KEF Reference 1s, which I thought were going to be my forever speakers.
A few comments - the Ref 1s are anything but "bright". Not in my system, or in two other friend's systems. I'm quite sensitive to anything bright. They are very neutral, and if anything, on the warm side.
I know the person mentioned in the PS Audio forums that went from the Ref 1 and the FR5s and have listened to their system with both speakers. The FR5s are more "lively", which for me would have probably translated to "bright" over time. The ribbon tweeter created a really large soundstage, which is something the KEFs also excel at. My friend likes them better, I probably would have stuck with the KEFs. A matter of taste. The cool thing is that PS Audio has a generous return policy, so you could try them for up to 30 days and return them.
The only speakers in that range that made me want them over the Ref 1s (besides my Gershman Studio XD) were Joseph Audio Pulsar Graphenes. I'm sure there are other speakers that I haven't heard that are "better" also.
As much as I love the Gershman Studio XD, I'm not sure I'd recommend them with the Mimas. They have a similar sensitivity rating to the Ref 1, but are much harder to drive. I had 160 watt monoblocks and they couldn't quite wring out the best from the Gershmans. I replaced them with the PS Audio M1200 Stellar 600 watt monoblocks and am now a happy camper. The JA Pulsars are easier to drive.